. >> reporter: as wheeler-dealer oilmanj.r. ewing, hagmanruled over the southfork ranch and the tv ratings for 13 years beginning in the spring of 1978. >> tramp. name of the game is huge. you're destroying everything that daddy spent his life. >> reporter: episode after episode the duplicitous j.r. schemed and double-crossed his way to the top. until in the cliff-hanger season finale in the spring of 1980 somebody in his inner circle had had enough. (gunfire). dallas fans spent an entire summer asking themselves the question, who shot j.r.? it was a testament to the acting abilities of the real larry hagman. the son of singer mary martin, larry hagman's own career was launched in the 1960s with a role at astronaut anthony nelson in the sit-com i dream of jeannenie opposite barbara eden playing the part of the jeannenie. >> i must have gone further into orbit than i thought. >> osgood: though other tv and film roles followed, it was dallas that put him on the map. >> get me the police. reporter: when the identity of j.r.'s assailant was revealed in november of 1980, as many as 83 million p